172721842 has 8 divisors (see below), whose sum is σ = 262732032. Its totient is φ = 85144500.

The previous prime is 172721827. The next prime is 172721849. The reversal of 172721842 is 248127271.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 172721798 and 172721807.

It is not an unprimeable number, because it can be changed into a prime (172721849) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 608034 + ... + 608317.

It is an arithmetic number, because the mean of its divisors is an integer number (32841504).

Almost surely, 2^172721842 is an apocalyptic number.

172721842 is a deficient number, since it is larger than the sum of its proper divisors (90010190).

172721842 is a wasteful number, since it uses less digits than its factorization.

172721842 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1216424.

The product of its digits is 12544, while the sum is 34.

The square root of 172721842 is about 13142.3682036382. The cubic root of 172721842 is about 556.9066711426.

The spelling of 172721842 in words is "one hundred seventy-two million, seven hundred twenty-one thousand, eight hundred forty-two".